OdinJobs have a interesting resources for PHP developers, an US job market overview for PHP related jobs. Beside that data are available for 2008-2009 only you can have an idea about salary range of PHP related jobs in different US states. I have found many new jobs from the website search but unfortunately it’s not yet available in the market overview.
According to Odin’s PHP Salary Histogram salaries are between from $20K to $180K, while average salary range around $70K. Notice that Odin collects jobs from job boards, corporate websites, groups etc.
odin salary histogram
PHP jobs demand in US seems concentrated mainly in New York, Illinois, Texas, California, and Massachusetts, with a peak in California with 28229 jobs overall. But from a salary point of view, Idaho got the highest salaries with $100K median salary, followed by Washington, Arkansas, California, and Massachusetts.
More trends available at Odin PHP Job Market overview